Modified Wood-Protein Adhesive Bondline Strength Development during Curing

New adhesives from renewable sources are of interest for wood composites for both ecological and economic reasons. Both formaldehyde emission and the availability of petrol are driving forces behind the research to find alternatives for synthetic resins. However, the bonding strength and water tolerance of natural adhesives are often insufficient. Increasing the compatibility of wood towards the hydrogen bonding common in natural adhesives can produce composites with stronger cross-linking and thus better mechanical and water-tolerance properties. The compatibility of a wood surface towards natural adhesives can be improved by chemical and mechanical means. The effect of chemical activation, such as acetylation, on the adhesive bond strength was evaluated on beech (Fagus silvatica L.) veneers using an automatic bond evaluation system (ABES).